A driver alert system is known, for example, as described by BP 0 856 432 A2 and US 2003 0197601 A1.
When the driver alert system of the prior art is activated by supplying a voltage to the electric motor in order to cause vibrations in the steering wheel rim, the rotation frequency of the motor may accelerate only slowly and under negative circumstances may even be trapped at a resonance frequency of the steering wheel column. This could be overcome by using a stronger electric motor which however would require more space and leads to an increase of costs. Similarly, when the electric motor is stopped at the end of a vibration period, the motor may decelerate only slowly.
It is the object of the invention to provide a compact and reliable driver alert system with short response times.